Operating system for tractor

ABSTRACT

An operating system for a tractor to which an implement is attachable, the operating system comprises: a steering wheel provided rearwardly of a hood that houses an engine located in a forward region of the tractor; a control panel provided rearwardly of the hood and adjacent the steering wheel; a center cover extending generally vertically below the steering wheel; an operation lever provided at a position laterally of the control panel; a valve unit with a pair of spools, the valve unit being located at a lower position with respect to the steering wheel and being covered by the center cover; a link mechanism that links the operation lever and the pair of spools, the link mechanism being covered by the center cover.

BACKGROUND OF THE INVENTION

The present invention relates to operating systems for the front loaderof a tractor.

An implement is often connected to a tractor. When a front loader isconnected to a front portion of a tractor as one such accessoryimplement, then, as shown in JP H4-110406U, for example, the left andright support beams of the front loader are connected via brackets tomounting seats that are provided to the left and right below the frontportion of the driving portion, and to one of the brackets are attachedvalves for raising and lowering the boom and for rotating the bucket andan operation lever for operating these.

The job of the front loader is to raise and lower the boom and rotatethe bucket while repeatedly moving back and forth in the longitudinaldirection of the tractor, and thus it is desirable for the loaderoperation lever to be furnished at a high position next to the steeringwheel, and to this end, frames are provided specifically to support theoperation lever at a high position, resulting in a configuration inwhich the loader operation structure is large and has many structuralcomponents.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an operating system that hasan operation lever for a front loader that can be operated with easewhile operating the steering wheel. A further aim of the invention is toprovide an operating system that can provide a more comfortable spacefor the operator because the essential components of the operatingsystem are furnished in the center frame.

An operating system in accordance with the present invention for atractor to which an implement is attachable, the operating systemcomprises: a steering wheel provided rearwardly of a hood that houses anengine located in a forward region of the tractor; a control panelprovided rearwardly of the hood and adjacent the steering wheel; acenter cover extending generally vertically below the steering wheel; anoperation lever provided at a position laterally of the control panel; avalve unit with a pair of spools, the valve unit being located at alower position with respect to the steering wheel and being covered bythe center cover; a link mechanism that links the operation lever andthe pair of spools, the link mechanism being covered by the centercover.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall lateral view of the tractor;

FIG. 2 is a lateral view of the engine portion;

FIG. 3 is a lateral view of the engine hood in the open state;

FIG. 4 is a plan view showing a portion of the engine hood;

FIG. 5 is a perspective view showing a stay for reinforcing the hood;

FIG. 6 is a front view of the frame structure;

FIG. 7 is a rear view of the frame structure;

FIG. 8 is an exploded lateral view of the frame structure;

FIG. 9 is a front view showing the partition portion of the framestructure;

FIG. 10 is a front view showing the support frame portion of the framestructure;

FIG. 11 is a front view of the interlocking lock mechanism;

FIG. 12 is a lateral surface view of the tractor front to which a frontloader has been mounted;

FIG. 13 is a lateral view of the steering portion;

FIG. 14 is a front view of the steering portion;

FIG. 15 is a rear view of the front loader operation portion;

FIG. 16 is a rear view showing the lever lock state of the front loaderoperation portion;

FIG. 17 is a plan view showing the lever lock state of the front loaderoperation portion; and

FIG. 18 is an exploded perspective view of the lever base portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a tractor having an engine portion structure according tothe invention. This four-wheel drive tractor is driven by front wheels 1and rear wheels 2, on the front side of the tractor is provided anengine portion 5 made of an engine 3 that is covered by an engine hood4, a driver's seat 6 is disposed between the left and right rear wheels2, and behind the driver's seat 6 is provided a rollover protectionframe 7 with a top horizontal bar and a pair of vertical supportcolumns.

The engine hood 4 is made of a stationary lower hood 4 a and an upperhood 4 b that can be slid open and closed vertically about a fulcrum pat a front-portion thereof, and the engine 3 and the various machinecomponents that are associated with the engine 3 are accommodated in theengine compartment R that is formed by the engine hood 4 and disposed infront of a radiator 8.

A frame structure 10 serving as the rear wall of the engine portion 5 isprovided vertically at the rear portion of the engine compartment R, andto the frame structure 10 are mounted a panel cover 11 and a centercover 12 below the panel cover 11.

An instrument panel 13 and various switches are installed in the panelcover 11, and a ventilation opening 14 whose structure blocks out dustis formed in the center cover 12. The outside air that has beenintroduced through the ventilation opening 14 is sucked in by a radiatorfan 9 and guided to the radiator 8, after which the air flows forward inthe engine compartment R, discharging heat within the room to theoutside through ventilation openings 15 in the front face and lateralfore portions of the engine hood 4.

The lower hood 4 a making up the lower portion of the engine hood 4 isformed in the shape of a flat bracket that is open to the rear and isfixedly joined to a vehicle frame 16, and the ventilation openings 15are formed in a meshed pattern in the forward face and the lateral facesof the lower hood 4 a.

The upper hood 4 b is pivotably connected to an upper end portion of afixed support frame 17, which extends vertically from the vehicle frame16, in such a manner that it can swing about the fulcrum p, and a pairof left and right front lights 18 are attached to the front end portionof the upper hood 4 b. A gas spring 20 is engaged between the lateralcenter region of a fulcrum fitting 19 that is attached to the innersurface of the fore end portion of the upper hood 4 b and a stay 17 athat extends from the lateral center region of the fixed support frame17, and as shown in FIG. 3, the extension bias properties of the gasspring 20 are set in accord with the weight of the upper hood 4 b sothat the extension bias of the gas spring 20 safely holds the upper hood4 b at a open position that allows maintenance tasks to be performed.

The upper hood 4 b is also designed so that it is held in a closedorientation by an interlocking lock mechanism 21 that is disposed on itsfree-end side. That is, as shown in FIG. 3, an interlocking pin 22 isfastened to a center region of the rear free end portion of the upperhood 4 b via a support fitting 23, and a hook-shaped lock fitting 24that engages the interlocking pin 22 is pivotably attached to the upperend portion of the frame structure 10 in such a manner that it canhorizontally rotate about a fulcrum a. The lock fitting 24 is rotativelybiased in the engaging lock direction by a spring 25, and as shown inFIG. 11(I), the interlocking pin 22 of the upper hood 4 b, which isclosed in resistance to the gas spring 20, engages the lock fitting 24and holds the upper hood 4 b in the closed position.

An operation lever 24 a is joined to the lock fitting 24 and extendsabove the panel cover 11, and as shown in FIG. 11(II), horizontallyswinging the operation lever 24 a to rotate the lock fitting 24 inresistance to the spring 25 has the effect of slightly lifting the upperhood 4 b, whose lock has been released, due to the bias applied by thegas spring 20, and simply by putting one's fingers there and pivotingthis open with a wide swinging action, the upper hood 4 b can be held inthe open position by the gas spring 20.

It should be noted that, as shown in FIGS. 3 to 5, a stay 26 that islong in its lengthwise direction and that spans between the fulcrumfitting 19, to which the gas spring 20 is connected, and the supportfitting 23 of the interlocking pin 22, is furnished in a verticalorientation along the inner surface of the roof of the upper hood 4 b,and reinforces the upper hood 4 b, which is a resin mold. Thus, theupper hood 4 b is kept from bending under the upward bias force appliedby the gas spring 20 when its rear end is fixed in the interlockedstate.

As shown in FIG. 8, the frame structure 10, which serves as the rearwall of the engine portion 5, is made by joining a partitioning portion10A that is aluminum cast and horizontally wide and flat in thelengthwise direction, and a support frame portion 10B that is aluminumcast as well and divided into left and right portions, and the portions10A and 10B are joined by six threaded bolts 27 that position the two atappropriate locations in the lengthwise direction.

As shown in FIG. 6, the partitioning portion 10A of the frame structure10 is formed at the same width as the lateral width of the rear endportion of the engine portion 5, and the rear end of the engine hood 4and the front end of the center cover 12 are disposed along the outercircumference of the partitioning portion 10A. The air intake portion ofthe radiator 8 is furnished in a large opening 28 that is formed in acentral portion of the partitioning portion 10A, and the outside airthat is taken in through the ventilation opening 14 of the center cover12 is guided to the radiator 8 by way of the frame structure 10. A stepsupport portion 10 c is provided projecting horizontally outward fromthe left and right lower end portions of the partitioning portion 10A,and the left and right front of a step 29 that is disposed in the feetarea of the driver's seat 6 rests on and is fastened to the step supportportion 10 c. A recessed portion 30 that is bent downward in the shapeof a hook is formed in the left and right outer circumference portionsof the partitioning portion 10A, and wiring and hydraulic hoses H areinserted into the recessed portion 30 from the side and are safely heldon the bottom side of the recessed portion 30.

As shown in FIG. 10, the left and right support frame portions 10B ofthe frame structure 10 are joined by bolts, and at their lower endportions are furnished with a pair of left and right leg portions 10 d.The leg portions 10 d extend wide to the rear and rest on and are boltedto the vehicle frame 16, and this allows the entire frame structure 10to be safely fastened upright.

A box-shaped portion 10 e that is open in the lengthwise direction isprovided in the upper half of the support frame portion 10B, and forms abattery support portion B. The battery support portion B is formedprojecting rearward, a predetermined distance upward away from the legportions 10 d, such that a battery 31 can be inserted into the innerspace of the battery support portion B, which is formed in the shape ofa box, from the rear and fixedly attached. It should be noted that therear end of the box-shaped portion 10 e and the vehicle frame 16 areconnected by a stay 32 and serve as reinforcement for the batterysupport portion B, which receives the weight of the battery. Openings 33are formed in the left and right lateral faces of the box-shaped portion10 e, and these improve air circulation within the battery containmentspace and make the battery support portion B more lightweight.

A mounting seat 10 f extends rearward and upward on an upper portion ofthe battery support portion B, which is formed in a box shape, and byconnecting this to a hydraulic controller 34 for power steering, theleft and right partitions of the support frame member 10B are joined atan upper portion as well. An operation shaft 35 to which a steeringhandle 36 is attached extends upward from the hydraulic controller 34.The hydraulic controller 34 delivers an amount of pressurized oil thatcorresponds to the amount that the steering handle 36 has beenrotatively actuated, in a direction that corresponds to the direction inwhich the handle has been actuated, supplying it to hydraulic cylinders37 for front wheel steering via the hydraulic hoses H.

The leg portions 10 d also function as valve support portions V, and asshown in FIG. 14, this allows a support plate 38 to be attached to theupper surface of the left and the right leg portions 10 d, and a valve39 (valve unit) can be attached onto the support plate 38.

The valve 39 is for driving hydraulic drive-type accessory implements,and FIGS. 12 to 14 show a tractor, and the steering portion thereof, inwhich a front loader 40, which is one example of an accessory implement,has been connected to the front of the vehicle.

The front loader 40 is made of a pair of left and right support frames42 that are fixedly joined in a detachable manner to support brackets41, which are provided at the left and the right of the front portion ofthe tractor machine 1, a pair of left and right booms 43 that areconnected to the upper end portion of the support frames 42 in such amanner that they can be swung vertically, and a bucket 44 that isconnected to the left and right booms 43 over their front ends in such amanner that it can rotate vertically, and the booms 43 are lifted up anddown by a lift cylinder 45 and the bucket 44 is rotatively driven by atilt cylinder 46.

An operation lever 47 for operating the valve 39 is disposed on theupper right side of the frame structure 10, and the connecting structurefor linking the valve 39 and the operation lever 47 is described below.

The valve 39 is furnished with two spools 48 and 49 that can slidelaterally and that project to the right of the machine, where the onespool 48 can be slid between three positions to select extension,retraction, or an intermediate stationary state of the lift cylinder 45,and the other spool 49 can be slid between three positions to selectextension, retraction, or an intermediate stationary state of the tiltcylinder 46.

The operation lever 47 and the two spools 48 and 49 are operativelyconnected by a link mechanism 50, and their structures are shown indetail in FIGS. 14 and 15.

A support bracket 51 is bolted to an area on the right side of the upperportion of the frame structure 10, and a lever spindle 53 is fitted intoand supported by a lateral boss portion 52, which is provided in thesupport bracket 51, in such a manner that it can rotate about a lateralaxis x. The operation lever 47 is linked to a rotating fitting 54 thatis connected by pins to the outer end portion of the lever spindle 53 insuch a manner that it can rotate to the left and right about alongitudinal axis y that is at a right angle to the lateral axis x, andthus the operation lever 47 is supported in such a manner that it canswing in a cross about the two perpendicular axes x and y.

An operation arm 55 is integrally connected to the inner end portion ofthe lever spindle 53, and the operation arm 55 and a bell crank 56 thatis operatively connected to an end portion of the spool 48 for the liftcylinder are operatively connected via a push-pull rod 57 that is longin the vertical direction. The rotating fitting 54 connected to theoperation lever 47 and a relay bell crank 58 that is pivotably linked tothe support bracket 51 in such a manner that it can rotate about afulcrum z in the longitudinal direction are operatively connected to oneanother by way of a rod 59, and a bell crank 60 that is operativelyconnected to the spool 49 for the tilt cylinder and the relay bell crank58 are operatively connected to a push-pull rod 61 that is long in thevertical direction.

Operatively connecting the operation lever 47, which can be actuated ina cross shape as above, and the two spools 48 and 49 via the linkmechanism 50 allows the lift cylinder 45 to be actuated by swinging theoperation lever 47 in the longitudinal direction and allows the tiltcylinder 46 to be actuated by swinging the operation lever 47 in thelateral direction.

The relay bell crank 58, the push-pull rods 57 and 61, and the valve 39are covered and hidden by the center cover 12, and the outside air thatis sucked in through the ventilation openings 14 of the center cover 12and circulated toward the radiator 8 cools the valve 39 and the battery32.

The support bracket 51 is provided with a lock lever 62. The lock lever62 is provided connected to a spindle 63 that is supported in such amanner that it can swing about a longitudinal axis d, and can beswitched between and held in two separate states via a toggle spring 64.That is, as shown in FIG. 15, when the lock lever 62 is swinginglytoggled to an orientation in which it faces the machine interior, a locklip 65 that projects from the spindle 63 is moved from below therotating fitting 54 to an away position in the machine interior, therebyallowing rotation of the rotating fitting 54 about the x and y axes. Asshown in FIG. 16, when the lock lever 62 is toggled to an orientation inwhich it faces away from the machine, the lock lip 65 becomes positioneddirectly below the rotating fitting 54 and the interlocking portion 54 athat projects downward from the rotating fitting 54 engages a lock hole66 that is formed in the lock lip 65, and this prevents rotation of therotating fitting 54 about the x and y axes and thereby keeps theoperation lever 47 from being actuated inadvertently.

Other Embodiments

(1) It is also possible to adopt a configuration in which the batterysupport portion B provided in the frame structure 10 is in the shape ofa box that opens to the side, so that the battery 31 is inserted andremoved from the side.

(2) In the foregoing embodiment, the leg portions 10 d for connecting tothe vehicle frame 16 were formed in the support frame portion 10B, butit is also possible to adopt a configuration in which the step supportportion 10 c and leg portions 10 d functioning as valve support portionsV are formed in a single unit with the partitioning portion 10A.Further, it is also possible to form the entire frame structure 10through aluminum-pressure die-casting.

1. An operating system for a tractor to which an implement isattachable, the operating system comprising: A steering wheel providedrearwardly of a hood that houses an engine located in a forward regionof the tractor; a control panel provided rearwardly of the hood andadjacent the steering wheel; a center cover extending generallyvertically below the steering wheel; an operation lever provided at aposition laterally of the control panel; a valve unit with a pair ofspools, the valve unit being located at a lower position with respect tothe steering wheel and being covered by the center cover; a linkmechanism that links the operation lever and the pair of spools, thelink mechanism being covered by the center cover.
 2. An operating systemas defined in claim 1, wherein the operation lever extends from aposition which is laterally projected from a side surface of the controlpanel.
 3. An operating system as defined in claim 1, wherein theimplement is a front loader.
 4. An operating system as defined in claim1, further comprising: a frame structure that is located in a rear endregion of the hood and that defines an engine compartment in cooperationwith the hood.
 5. An operating system as defined in claim 4, wherein theframe structure is covered by the control panel and the center cover. 6.An operating system as defined in claim 4, wherein the frame structurehas a mounting seat at an upper position thereof for supporting thesteering wheel.
 7. An operating system as defined in claim 4, whereinthe frame structure has a support bracket at a location near an upperportion thereof for supporting the operation lever.
 8. An operatingsystem as defined in claim 4, wherein the frame structure has a batterysupport portion at a higher location than the lower end of the framestructure.
 9. An operating system as defined in claim 8, wherein theframe structure has a valve support portion at a lower position withrespect to the battery support portion, the valve support portionsupporting the valve unit.
 10. A tractor to which an implement isattachable comprising: a plurality of wheels; a vehicle body supportedby the plurality of wheels; an engine supported at a forward position ofthe vehicle body; a hood that houses the engine; a steering wheelprovided rearwardly of the hood; a control panel provided rearwardly ofthe hood and adjacent the steering wheel; a center cover extendinggenerally vertically below the steering wheel; an operation leverprovided at a position laterally of the control panel; a valve unit witha pair of spools, the valve unit being located at a lower position withrespect to the steering wheel and being covered by the center cover; alink mechanism that links the operation lever and the pair of spools,the link mechanism being covered by the center cover.
 11. An operatingsystem as defined in claim 10, wherein the operation lever extends froma position which is laterally projected from a side surface of thecontrol panel.
 12. An operating system as defined in claim 10, whereinthe implement is a front loader.
 13. An operating system as defined inclaim 10, further comprising: a frame structure that is located in arear end region of the hood and that defines an engine compartment incooperation with the hood.
 14. An operating system as defined in claim13, wherein the frame structure is covered by the control panel and thecenter cover.
 15. An operating system as defined in claim 13, whereinthe frame structure has a mounting seat at an upper position thereof forsupporting the steering wheel.
 16. An operating system as defined inclaim 13, wherein the frame structure has a support bracket at alocation near an upper portion thereof for supporting the operationlever.
 17. An operating system as defined in claim 13, wherein the framestructure has a battery support portion at a higher location than thelower end of the frame structure.
 18. An operating system as defined inclaim 17, wherein the frame structure has a valve support portion at alower position with respect to the battery support portion, the valvesupport portion supporting the valve unit.